Answer:
8
Step-by-step explanation:
when multiplying two negative, it turn into a positive.
The 2 minuses cancel out and becomes 8.
The third one
consider the following image
7.6 should be the answer.
x=−y−2z+3
x=y+32z+1
x=13y+23z+13
Answer: 89 x 87 =7,743